aerodynamic analysis.doc

8/12/2019 aerodynamic analysis.doc

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AbstractDrag and its coefficient can be calculated by means ofvirtual environmental simulation with the help of wind tunnel or through

computer software. The use of computer software makes it possible to be

in time and cost savings. Numerical methods for doing this can be the

fluid flow by a two dimensional or three-dimensional model of the vehicle

structure to be resolved. This paper has tried to use the ANSYS !" and

the e#uations governing fluid flow combined with standard model solved

by using the appropriate boundary conditions. The study results of the

aerodynamic analysis of the air flow$ pressure distribution and drag force

on the vehicle. !ew design modifications in the form of attachable

accessories have been suggested in order to reduce the drag coefficient.

These modifications have shown a drag reduction of %&.'() at a speed of

*+ km,h with the drag coefficient reduced to +.* from +.'$ therebyreducing the fuel consumption by about appro/imately %&.'()$ which

means$ there is a saving of '.%&0 of petrol for every full tank refill. These

observations are validated using wind tunnel testing on a %1'2 scaled

model using momentum deficit method.

3eywords: Automotive Aerodynamics4 Drag oefficient4 !uelonsumption4 Numerical Analysis4 Drag pressure4 5ind Tunnel

Techni#ues$ 6omentum Deficit 6ethod$ !orce 7alance 6ethod

INTRODUCTION

Tata Nano was envisioned in 2003 to become a peoplesca! t"at is a##odable b$ eve$bod$! mainl$ t"e cit$ dwelleso# India% &ince its deb't in 200(! t"e sales o# Tata Nano "ave)one down temendo'sl$% In t"e #ist *'ate o# 20+3! n'mbe

o# ve"icles sold in t"e mont"s o# ,an'a$! -eb'a$ and .ac"

wee +/0! +/0/ and +/01 'nits! espectivel$% "en it was

#ist conceived! a ta)et pice o# +00!000 'pees was

establis"ed b't it cept 'p to abo't +2!000 'pees in ve$

s"ot time d'e to a steep incease in pice o# aw mateials and

inp't costs% dded to t"is! t"e soain) #'el pices! its no

lon)e an easil$ a##odable ca% &t'dies "ave s"own t"at +/

pecenta)e o# t"e #'el in a ve"icle is 'sed to ovecome

mec"anical #iction in t"e en)ine! / pecenta)e o# t"e #'el is'sed to ovecome t"e ollin) esistance and da) is esponsible

#o t"e emainin) 0pecenta)e% ca wit" low da) #oce

enco'ntes lesse #iction t"an a ca wit" "i)"e da) #oce%

4ence! a smalle en)ine is e*'ied to dive s'c" a ca w"ic"

event'all$ lowes t"e #'el cons'mption% In t"is pape we

#oc'ssed on ed'cin) t"e oveall da) #oce on t"e ve"icle! and

5+ 6 sst% 7o#! Dept% o# eona'tical and 'tomobile 8n)) .ail:mani9andan%mmanipal%ed'!! 2!3! 6 &t'dents! .anipal Instit'te o#

Tec"nolo)$! .anipal Univesit$! ;anata9aect

ssociate! Indian Instit'te o# Tec"nolo)$! ?and"i Na)a! India%

t"eeb$ bin)in) down t"e #'el cons'mption! "ence ma9in)t"e Tata Nano a)ain a #avo'ite amon) t"e Indian masses%

@IT8RTUR8 R8AI8

B'


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obtained #o eac" velocit$% T"eoetical val'es wee validated

b$ wind t'nnel test 'sin) pess'e tappin)s and pitot t'bes on

a +:+/ model o# t"e ve"icle%

ni9et ;'l9ani! & A &atis" and A &aavanan 829 nal$sed

t"e #low patten o# a convetible #o two desi)ns i%e% wit" oo#

closed and wit" oo# open% &edan models wee ceated 'sin)'todes9 Invento so#twae! mes" )eneation was done 'sin)

?ambit and #inall$ pocessed in -l'ent 'sin) 9


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I.7ROAI&TION

T"e vaio's desi)n modi#ications t"at wee anal$Fed ae as

below

i dam

n ai dam ed'ces t"e aiect'e dawn was t"at t"e ma>oit$ o#

t"e da) #oce on t"e ve"icle wo'ld be d'e to t"e wa9e e)ionbe"ind t"e ca and not mainl$ d'e to #ontal ai impact%

Rea spoile

Da) is ai p's"in) a)ainst t"e ve"icle as it moves% T"e #aste

t"e ve"icle moves! t"e moe da)! w"ic" e*'ies moe powe

and #'el to maintain t"e speed% spoiles p'pose is to

ed'ce da)% n$ added s'#ace in ai#low adds to t"e da)%4oweve! )ood spoile desi)ns can ed'ce t"e oveall da) o#

$o' ve"icle%

4ence! t"e p'pose o# an a'tomotive spoile is to dis'pt! o

spoil! t"e ai#low ove t"e ca to impove pe#omance% T"is

desi)n ed'ced t"e da) #oce to +%322N

Rea pot'sion

ea pot'sion was desi)ned as s"own in t"e #i)'e PQQQ

Rea sceen

T"e best desi)n modi#ication came in t"e #om o# a ea

sceen% T"e sceen was /mm in t"ic9ness and di##eent

distances #om t"e ca ea wee anal$Fed%


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T"e epected e##ect o# aeod$namic da) ed'cin) is ac"ieved

#o t"e sa9e o# vote t"at oi)inates between ve"icle models

ea wall and sceen t"e vote enables noectives and Investi)ationsX! w"ite pape!s'bmitted to NRC Decadal &'ve$ Inne 7lanets &'bpanel! ')'st20++%


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P ColoFFa! %,%! Wis"ips #o 7laneta$ 8ploation,N&KCR

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